Silver Stackers

Buying from a trusted source helps, as does buying certain coins.

Depending on your location, there's also a couple of places that have offered to forum members the use of their XRF (X-ray fluorescence) equipment that can test the metal content of pretty much anything - for example, identifying if a sovereign is a genuine 22k sov, or whether it's a 14k jewelers copy.

Many members do buy scales - this is super handy for testing coins - for example on the weekend I was shown some fake silver rounds, that were an obvious giveaway due to their weight. For the needs of the average stacker, the cheap digital scales off eBay are great for coins (get the 300-500g 0.01g accuracy ones). You would need larger scales for kilo bars.

Easiest thing to do as a new stacker is stick to the "known" stuff like Perth Mint coins and bars (both gold & silver), and 1966 50c coins. Read, read, read - and read some more. There's plenty of fake stuff out there like 100 Mills, German Silver, HGE, Layered, etc that are all just marketing terms for fake alloys or plated copper.

If your looking at buying bars i would stick to Perth mint or PAMP imo they are the best quality out there and internationally recognized.

Fisch Wallet #5 - Gold   
American Buffalo (1oz)
Vienna Philharmonic - Austria (1oz)
Australian Nugget/Kangaroo (1oz)*
*also Lunar 1996-2007
(3 Detectors)

http://www.fisch.co.za/orderonline.htm

Since you are in the Gold forum I'm assuming you are talking about small bars (1ozt or less)  Calculations from measurements are very dodgy unless all surfaces are dead flat, corners are sharp rightangles  etc.
A far more accurate way is to work out the SG (Density) from a couple of weighings, I have no gold bars so will demonstrate a simple method using a 1 ozt silver coin. -  NOTE: I had scales last week that measured to 2 decimal places - Cost $7 - Neighbor offered me $20 for them *Sold* Have 2 new ones ordered. - But at the moment only scales I have only gp to 1 Decimal place.  So this will not be accurate but shows the method.

First - Weigh the Dry coin or bar.  Photo shows 31.6g (Actual weight is higher.)

Next ,get a dixie Cup with enough water in it so you can immerse the coin or bar without it touching the side or bottom of the cup, 
Place cup and water on scale the press TARE to zero the scales.

Make up a sling to hold the coin or bar with silk threads or fine waxed cotton, and lower it into the water without touching the cup.
In photo Im cheating and using a pair of tweezers (not good - tweezer ends in water adding extra volume.)
You are not lowering weight into water - you are lowering VOLUME - You are holding the weight.
Read the weight showing on scales when coin or bar is fully submerged.  This is the weight of the displaced water.
Photo shows 3.0g (from previous weighings on other scales this is normally 3.01 or 3,02 on a 1 ounce silver coin...)

So to find the SG (Density) divide the dry weight by the second weight  31.6 / 3.0 = 10.53  (SG of silver is 10.5)
with 2 decimal place scales you will get greater accuracy

This method with good scales will give very accurate results,  if the coin was a silver plated copper coin it would have shown a SC of about 8.9
and will work on any size weight or material - Below are some SG's for various metals

Silver, 10.5.
Platinum, 21.4.
Palladium, 12.0.
Copper, 9.0.
9ct, 10.9 to 12.7.  - Depends on alloy mix
14ct, 12.9 to 14.6. -  Depends on alloy mix
18ct Yellow, 15.2 to 15.9 . - Depends on alloy mix
24ct Gold, 19.3. .

This method will sort out most fakes, but if in doubt use other testing methods available

i'm using the one at my work, (Chem teacher) you just reminded me i'll get kids to clean some of my coins  (child labour does work well)

Yep - Its a dead easy test to do and its quite accurate, sometimes the simple way is the best way.
I thought there must be a few people in here that have known fake coins and was hoping someone would test using this method and report result,  I'm curious to know just how close can they get the  fakes to the real ones

Another way is to use vernier callipers to measure the diameter and a micrometer to measure the thickness.
Volume = area x thickness.
Density is mass ( i.e. weight ) / volume.
Try to measure near the centre and avoid the rim which can be raised.
Most fakes are easily spotted as underweight and slightly thicker.

Reduced weight on UNC looking coins is worth investigating.
If the diameter is correct ( most fakes are ) and the weight seems low then sometimes this can be wear so should be thinner. Fakes however will be thicker.

What is a fisch worth and where does one obtain one?  Sorry for the laziness in tracking one down but I am sure it would be quicker to enquire here and I more reliable.  Thanks in advance.

Also, the knock-off is here: http://www.i-c-g.biz

I've tested it and it works.

I am looking at the i-c-g as well.

Questions:  What is 2 rand? and would you personally perfer to pay a bit more for Fisch or just get a scale off ebay?

We are starting with a set of five scales useful in validating the following bullion coins, the most frequently counterfeited around the world: Krugerrand, American Double Eagle, Isle of Man, Angel Britannia (1, 1/2, 1/4, and 1/10 oz), British Sovereign, and 2 Rand

Thanks goldpelican,  any specific realiable digital scale recommandation and where I can purchase one?

Cheers
A

great
bought one of those cheap scales
thanks for all the help guys!